The spectral characteristics of an integrated acousto-optic tunable filter (AOTF) as well as its responsivity to the rf driving signal and sensitivity to temperature changes are experimentally investigated and quantified using a diode-laser-based interrogation system. A spectroscopic technique, exploiting the rf frequency modulation of the laser beam and the phase-sensitive detection of the AOTF transmission, has been used for this purpose. That allows for the generation of a dispersivelike signal, which serves as a reference for tracking any wavelength change of the filter's peak with high resolution. The possibility of using the integrated AOTF as a spectrum analyzer with this interrogation scheme for fiber Bragg grating (FBG) strain sensing is also discussed.
© 2006 Optical Society of America
Original Manuscript: February 21, 2006
Revised Manuscript: July 24, 2006
Manuscript Accepted: August 23, 2006
Antonio Di Maio, Mario Salza, Gianluca Gagliardi, Pietro Ferraro, and Paolo De Natale, "Spectral characterization of integrated acousto-optic tunable filters by means of laser frequency modulation spectroscopy," Appl. Opt. 45, 9176-9181 (2006)